Brush-holder for dynamo-electric machines or motors.



0. E. K. ZAUHAU. BRUSH HOLDER FOR DYNAMO ELEOTRIG MACHINES 0R MOTORS.APPLIOATION FILED JAN. 10, 1907.

924,71 6. Patented June 15, 1909.

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m: uaRms PETERS c0.. wAsnmcr-an, nc G. E. K. ZAGHAU. BRUSH HOLDER POEDYNAMO BLEGTRIG MACHINES 0R MOTORS. APPLICATION FILED JAN. 10, 1907.924,716. Patented June 15,1909.

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Z mun time STATES earner CARL ERIC KRIS'lOFFltR Zn OHAU, OF MUSKEGON,MICHIGAN.

BRUSH-HOLDER FOR DYNAIMO-ELECTRIC MACHINES OR MOTORS.

Application filed January 10, 1907.

T 0 all whom it may concern:

Be it known that I, CARL ERIC KiiIsToF- FER ZACHAU, a subject of theKing of Sweden, residing at Muskeg-on, in the county of Muskegon andState of Michigan, have invented certain new and useful improvements inBrush-Holders for Dynamodilectric Machines or Motors, of which thefollowing is a clear and exact specification.

This invention relates to improvements in brush-holders fordynamo-electric machines or motors, and has for its primary object toprovide an improved brush-holder for dynamo -electric machines or motorsby which the brush is held in a manner to secure the most desirableresults, the construction employed in the device making it extremelysensitive so that it is adapted to rcspond immediately to slightvibrations due to an uneven commutator surface or other causes.

A further obj eot of the invention is to provide an improvedbrush-holder that is simple and economical in construction and employingas small a number as possible of operative parts and joints, thusdecreasing the number of wearing parts and lengthening the life of thedevice.

To the attainment of these ends and the accomplishment of other new anduseful objects, as will appear, the invention consists of the featuresof novelty in the construction, combination and arrangement of theseveral parts hereinafter more fully described and claimed and shown inthe accompanying drawings, illustrating an exemplification of theinvention and in which" Figure 1 is a side elevation view of the device,showing the carbon brushes in contact with the surface of a commutator.The bracket or frame is shown in section in this view in order todisclose more fully to view the operative parts. The section of theframe is taken approximately on line ].1, Fig. 2. Fig. 2 is a top planview of the de vice. Fig. 3 is a plan view of the device from the underside or from the side opposite to that from which the view is taken inFig. 2. Figs. 4 and 5 are views similar to Figs. 1 and 2, but show amodification of the invention by which the cam surfaces 1 and 1 form oneside of slots. This construction, which is shown as a modification ofthe invention, is found advantageous under conditions as hereinafterdescribed.

1 is the bracket or frame, which is an irregu- Specification of LettersPatent.

Patented June 15, 1909.

Serial No. 3 1,667.

lar member designed to furnish a convenient means of support for theoperative parts of the device. The upwardly extending flange 1 isdesigned to serve as a convenient means for attaching the device to anysuitable support on the machine. The transverse rib 1 serves as a meansof strengthening the casting, and the depending members 1 and 1 whichare formed approximately at right angles to the body member, serve asconvenient means for attaching the brush holding frame and itsconnections. The transverse member 1 extending between the members 1'and 1 serves to strengthen the entire bracket or frame and also tofurnish a convenient means for attaching a spring or other elastic meansas hereinafter described.

2 is a link pivotally mounted in the depending members 1 and 1.bifurcated, the branch 2 extending to the depending member 1 and thebranch 2 extending to the member 1 Both of these branches may )0 pivotedto the frame or bracket 1 by the common pin 3 or in any other convenientmanner.

e is the brush holding frame, in the present embodiment adapted to holdthe common form of carbon brushes. This frame is pivoted at 5 to thefree end of the link 2 and is also provided with the upwardly extendingmembers 4 and l These members are provided near their upper extremitieswith the cross member 6, the extremities of which, it will be noted,extend beyond the sides of 4* and 1 and form trunnions or lugs whichcontact with the cam surfaces 1 and 1 which form a part of the dependingmembers 1 and 1 of the bracket 1. it will be apparent that thisconstruction affords a convenient means for the attachment of the springor other elastic means 7, the other end of which is attached to thememher 1. (/ross member 6 may be convenicntly cast integral with theupwardly extending branches of the frame 4 or formed individually andinserted, as shown in the present embodiment.

in Figs. 4 and 5 a modification of the memher or bracket 1 is shown bywhich the cam surfaces 1 and 1 are constructed, as one side of curvedslots, in which the ends of the cross member 6 are adapted to slide, theother sides of the slots being formed by the extensions 1 and 1 of themain frame. This construction, it will be apparent, secures the. ends ofpin 6 within the slots, and will pre This link is vent the frame frombeing tilted out of position, if any extreme irregularity on the surfaceof the commutator should strike the side or end of the carbon brushes 8and 9.

Heretofore it has been common to mount brush carrying frames on parallellinks in order that the brush, as it moves in relation to the surface ofthe commutator, may move in planes constantly parallel with each other.It is one of the purposes of the present invention to secure thisdesirable result with the use of but a single link in order to reducethe amount of mechanism required and to this end the cam surfaces 1 and1 describe arcs of circles whose radii are equal to the distance betweenthe pivotal points at the extremities of the link 2 and whose centersare determined by the location of the fourth corner of theparallellogram, of which the three known corners are the pivotal members3 and 5 and the transverse member 6 when the member 6 is held in itsnormal position against the cam surfaces 1 and 1 It will be seen thatthe line of tension of the spring 7 is such that the pull on thetransverse member 6 will constantly draw the upper end of the frame 4toward the bracket and consequently keep the extensions or trunnions atthe upper ends of 4 and 4 in constant engagement with the cam surfaces 1and 1 It will also be seen that the action of the spring 7 will be todraw the frame a downwardly until the link 2 will normally contact withthe transverse member 1 on the frame or bracket. From this constructionit will be seen that the movements of the frame 4 are the same thatwould result from the use of the common form of parallel linkconstruction and that in the present construction the upper link isomitted entirely, thus reducing the original cost and at the same timedispensing with two pivotal joints, which reduces to the minimum theliability of lost motion, thus making the present device extremelysensitive, a result which is also facilitated by reason of the fact thatthe spring acts directly on the brush-holding frame 4.

The brush in the present embodiment is shown formed of the carbon strips8 and 9 and are secured in the frame 4 by the set screws 10, which areheld in position by the lock nuts 11. The lower ends of carbons 8 and 9are adapted to contact with the com mutator surface 13. The members 12are inserted between the contact points of set screws 10 and the surfaceof carbons 8 and 9 and may be formed of any convenient malleable orductile material, as, for example, copper. it is also desirable toconstruct the movable parts, consisting of the frame a and the link 2,of as light a material as possible consistent with the strength andwearing qualities required of the parts, in order that the inertia maybe reduced as much as pos sible, a convenient material for this purposebeing aluminum.

The device may be provided with any suitable electrical connection, asfor example, the bonds l4 connecting the frame or holder 4 with thebracket 1.

The downward swing of link 2 is limited by the transverse member 1 andthe upward swing may be limited by the use of lugs 1 cast on thebracket.

In order that the invention might be fully understood the details of anembodiment thereof have been thus specifically described, but

l fhat I claim is In a device of the character described, thecombination of a bracket provided with a cam surface, a brush-holdingframe, a link pivotally secured to said bracket and aid frame, andelastic means adapted to hold said frame normally in engagement with thecam surface on the bracket.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, on this 7th day of January A. D.1907.

CARL ERIC KRISTOFFER ZAOHAU.

Vfitnesses HARRY SAWYER, (J. A. MILLS.

